It's running on Unreal Engine 3. https://twitter.com/MarkRein/status/209904125813587968 But I really doubt anything from rendering part of engine left here.
http://www.pcgamer.com/2012/06/07/star-wars-1313-running-on-unreal-engine-3-on-pc-at-e3-will-be-linear-and-light-on-jedi/ "Star Wars 1313 has delivered one of the most visually impressive demos of E3 2012 so far. Like Watch Dogs, it was running from a PC. Not only that, but CVG report that it was running on a tooled-up…